The forum page says that serious suggestions should go to the
bug database, so I submitted:
https://bugs.gentoo.org/show_bug.cgi?id=1744
but the resolution of the bug said that it should be posted to the forum.
I've included my bug report text here for discussion purposes,
as the resolver requested.
Basically this list of questions are ones that arose for me as
i was trying to understand gentoo from the web site.
(That also explains the somewhat inflammatory tone of the questions
as i was frustrated as I wrote them.)
Note that I've mostly just provided questions -- I honestly still don't
know the answers.

Q: Is there a way to configure the system so it will use a designated
cdrom, local directory, or remote repository as a cache of already
compiled binary packages? It would use that if there is one of
the same version available rather than recompiling from source.

A: ?

Q: What kernel version is gentoo tracking? Does it supply any of its
own kernel patches, or does it match some other 2.4 branch exactly?
Is the gentoo kernel also available over CVS? Does portage apply
to the kernel or just to the applications?

A: ?

Q: What command do I issue to determine which of my already installed
ports have a more recent version available?

A: ?

Q: Do the gentoo ports deal with the fixed install path braindamage
of a lot of packages? That is, does it try to solve some of the same
problems as http://www.openpkg.org/

A: ?

Q: How does gentoo/portage deal with the general problem of preserving
existing config files and data from old versions of software, while still
enabling new features when upgrading? Asked another way, to is mimic
the *bsd approach of being able to preverse/merge just /etc, and everything
else can be updated?

A: ?

Q: Is gentoo ever going to have an install procedure with fewer interactive
steps? Such asking the questions all at once, and then go get coffee, and
then it is done? Or supporting a special file of already-supplied answers?

A: ?

Q: It seems like this is unlike freebsd, which provides an integrated
release of a kernel with a chosen set of core services (such as dhcp, firewall,
mta, etc.), all of which are documented and configured in a single rc.conf:
http://www.freebsd.org/cgi/man.cgi?query=rc.conf&sektion=5
Rather gentoo seems more akin to the usual linux approach of choosing which
mta you want, which dhcp client you want, which pppoe you want, etc.,
and for each, you have to read their own documentation, and edit their
own individual files. Or am I missing something?

Q: Is there a way to configure the system so it will use a designated
cdrom, local directory, or remote repository as a cache of already
compiled binary packages? It would use that if there is one of
the same version available rather than recompiling from source.

A: Yes, see 'man emerge' or 'emerge --help', specifically the info on the flag --buildpkg.

mda wrote:

Q: What kernel version is gentoo tracking? Does it supply any of its
own kernel patches, or does it match some other 2.4 branch exactly?
Is the gentoo kernel also available over CVS? Does portage apply
to the kernel or just to the applications?

Q: What command do I issue to determine which of my already installed
ports have a more recent version available?

A: 'emerge --pretend --update world'

mda wrote:

Q: Do the gentoo ports deal with the fixed install path braindamage
of a lot of packages? That is, does it try to solve some of the same
problems as http://www.openpkg.org/

A: Currently the install paths are hardcoded to comply with the FHS standard.

mda wrote:

Q: How does gentoo/portage deal with the general problem of preserving
existing config files and data from old versions of software, while still
enabling new features when upgrading? Asked another way, to is mimic
the *bsd approach of being able to preverse/merge just /etc, and everything
else can be updated?

Q: Is gentoo ever going to have an install procedure with fewer interactive
steps? Such asking the questions all at once, and then go get coffee, and
then it is done? Or supporting a special file of already-supplied answers?

A. Who knows. It kind of defeats the purpose of being able to configure your system the way you want to. 'already-supplied answers' would be a lowest common denominator approach.

mda wrote:

Q: It seems like this is unlike freebsd, which provides an integrated
release of a kernel with a chosen set of core services (such as dhcp, firewall,
mta, etc.), all of which are documented and configured in a single rc.conf:
http://www.freebsd.org/cgi/man.cgi?query=rc.conf&sektion=5
Rather gentoo seems more akin to the usual linux approach of choosing which
mta you want, which dhcp client you want, which pppoe you want, etc.,
and for each, you have to read their own documentation, and edit their
own individual files. Or am I missing something?

A: You're not missing anything. You are responsible for choosing the packages that are best for what you want to do. However, when they are more than one package that provides a specific service, a virtual default is usually specified if the user hasn't previously chosen one.

> A: Yes, see 'man emerge' or 'emerge --help', specifically the info on the flag --buildpkg.

Which introduces another question -- are there online man pages
for portage?
The online portage manual and portage user guide make no mention
of --buildpkg, and in any event are a little too prolix for reference use.

>A: Currently the install paths are hardcoded to comply with the FHS standard.

This is an important point; it means that the design center is
significantly different from openpkg.org.
That is, it is oriented around the maintenance of a single machine
by a single user.
openpkg has features (such as control of versioned install dirs)
that facilitate network system administration.

ah, i see this mentioned also in a footnote of the portage user manual.
it is still unclear what it really does -- this is a non-trivial problem
(i don't want to choose between my old config and the new vanilla
config, but want assistance in config merging).
it is an issue not handled satisfactorily by freebsd (with /etc/upgrade),
but at least i understand it.

> It kind of defeats the purpose of being able to configure your system the way you want to. 'already-supplied answers' would be a lowest common denominator approach.

I didn't mean "already supplied by gentoo", i meant "already supplied
by the system administrator". This is an important feature of freebsd,
if you want to do an installation on dozens of machines.

> You're not missing anything. You are responsible for choosing the packages that are best for what you want to do.

This is another important point to make explicitly because gentoo
purports to be inspired in part by freebsd -- so i was expecting that
it was going to take a similar approach of releasing an integrated system
(with a centralized rc file and related documentation).
In this respect, gentoo follows the linux tradition.

Which introduces another question -- are there online man pages
for portage?
The online portage manual and portage user guide make no mention
of --buildpkg, and in any event are a little too prolix for reference use.

Please see

man ebuild
man 5 ebuild

Although note that these are slightly stale due to the rapid evolution of portage leading upt to the 1.0 release.

Of course, the best, most up to date documentation is always the source
see
/var/db/pkg/sys-apps/portage/portage-*/CONTENTS
for where to find it.

mda wrote:

>A: Currently the install paths are hardcoded to comply with the FHS standard.

This is an important point; it means that the design center is
significantly different from openpkg.org.
That is, it is oriented around the maintenance of a single machine
by a single user.
openpkg has features (such as control of versioned install dirs)
that facilitate network system administration.

There have been persistant grumblings about this. A user settable ${prefix} variable with the default to /usr might possibly be a future feature.

ah, i see this mentioned also in a footnote of the portage user manual.
it is still unclear what it really does -- this is a non-trivial problem
(i don't want to choose between my old config and the new vanilla
config, but want assistance in config merging).
it is an issue not handled satisfactorily by freebsd (with /etc/upgrade),
but at least i understand it.

Please see /etc/make.globals

CONFIG_PROTECT=

defines the directories to which no automatic file upgrades can be made. Instead, the new file is added as a ._cfg* file. The app-admin/gentoolkit has a very useful utility called etc-update in this regards. You can configure it to use vimdiff for example to easily merge any wanted changes.

CONFIG_PROTECT_MASK=

can be used to unprotect specific subdirectories of a masked directory if you would like those to auto-update.

Note: it usually a good idea to over-ride the default settings of these variables (and any other /etc/make.global default setting) in /etc/make.conf instead of directly editing make.globals.

mda wrote:

I didn't mean "already supplied by gentoo", i meant "already supplied
by the system administrator". This is an important feature of freebsd,
if you want to do an installation on dozens of machines.

Yes, that would be a nice feature. See below.

mda wrote:

> You're not missing anything. You are responsible for choosing the packages that are best for what you want to do.

This is another important point to make explicitly because gentoo
purports to be inspired in part by freebsd -- so i was expecting that
it was going to take a similar approach of releasing an integrated system
(with a centralized rc file and related documentation).
In this respect, gentoo follows the linux tradition.

A feature of portage is the concept of profiles. It is currently not exploited to its fullest. The idea being that there would be predefined profiles for webservers, mail servers, workstations, etc with essentially a list of packages that work well together to realize the intended function. See /etc/make.profile --> /usr/portage/profiles/default-1.0. Note that there already exists a profile for gcc-3.0 that you can point your /etc/make.profile symlink to.